I think the best topic is about the pandemic that we are facing right now, because everyone can relate about this topic.
You're about 6 months too late. Poems on Covid will have been done to death by now, and it's on its way out anyway. But to answer your question, I'll assume English is not your first language and you're asking what would be a good subject for the times. Well, poetry doesn't really work like that. There's no 'best topic' for poetry. If the poem's good it doesn't matter what the topic is.
I don't think the literary world is done publishing poems and other writing about the pandemic. It's likely something that will be written about for a long time. I do like poems that use current and/or historical events as the subject matter. And a good poem doesn't stop being a good poem even after a pandemic. I like poetry that taps into what's going on in the world. I think that's a better idea than then just a general poem that might not be so timely where it will lack the urgency that great literary works carry with them. And it's easy to say everything's been done, but that doesn't mean it can't be done in new and other ways.
